Hydraulic copying attachment for a lathe



Aug. 19,1969" w. 5 3,461,753

' HYDRAULIC comma ATTACHMENT son A LATHE Filed April 6. 1967 I z Sheds-Sheet 1 \j i I .IIFIJII? r W 13 22 20 1 V v zdwdmtfiww Aug. 19, 19 69 w. MEIER 3,451,753

' mmuuuc comma A'rucuuu'r FOR A LATHE Filed April 6. 1967 v v 2 Sheets-Sheet 2 United States Patent 3,461,753 HYDRAULIC COPYING ATTACHMENT FOR A LATHE Werner Meier, Winterthur, Switzerland, assignor to Oerlikon-Buhrle Holding Ltd., Zurich, Switzerland Filed Apr. 6, 1967, Ser. No. 628,939 Claims priority, application Switzerland, Apr. 15, 1966,

Int. Cl. B23b 3/28 US. Cl. 82-14 3 Claims ABSTRACT OF THE DISCLOSURE A hydraulic copying attachment for a lathe wherein the copying cylinder, in order to avoid any jamming, is mounted entirely at one side of the copying-cylinder housing above the center of frictional forces, that is to say above the point at which the frictional forces on the two gibs mounted between copying slide and saddle are in equilibrium, so that there is room for the stop drum, together with the distributing slide valve, at the other side of the housing, with their axes parallel to the cylinder, in order to be protected from dust. The counter stop is mounted on an arm, which is secured to the saddle and which extends through an aperture in the housing from the saddle to within range of the stop drum in the interior of the housing.

The invention relates to a hydraulic copying attachment for a lathe, the copying slide of which is guided on a dovetailed guide of the saddle, wherein the guide comprises two gibs, the frictional forces of which are in equilibrium through the center of frictional forces.

In particular, the invention relates to a hydraulic copying device for a lathe wherein a stop drum is adapted for axial displacement in order to influence the distributing slide valve of the copying cylinder on impinging on a counter stop connected to the saddle. Such a copying device has been described in German specification 1,187,887 as laid open for inspection.

It is an object of this invention to provide a copying slide with a copying-cylinder housing and to arrange the stop drum, the copying cylinder and its distributing slide valve in such a manner that the stop drum is not only protected from dust but also the copying cylinder ensures displacement of the copying slide without any jamming.

A further object is to provide means for bringing the counter stop, secured to the saddle, for the stop drum within range thereof in the interior of the copying-cylinder housing.

With the above and other objects in view which will become apparent from the detailed description below, a preferred embodiment of the invention is shown in the drawings in which:

FIGURE 1 shows a diagrammatic longitudinal sectional view of the attachment taken on the line II of FIGURE 3;

FIGURE 2 shows a diagrammatic longitudinal sectional view taken on the line IIII of FIGURE 3;

FIGURE 3 shows a crosssectional view on the line IIIIII of FIGURE 1; and

FIGURE 4 shows a plan view of the attachment, partially in section.

The dovetailed guide 2 with the two gibs 3 and 4 is mounted on the saddle 1 of a copying lathe which is otherwise not illustrated. The copying slide 5 reciprocates as usual in the guide 2 and carries the tool 6. The copying-cylinder housing 8 is flange-mounted on the copying slide 5.

In the housing 8, a copying cylinder 7 is mounted 3,461,753 Patented Aug. 19, 1969 above the one gib 3 with its axis parallel with the distributing slide valve 10 and with an axially displaceable stop drum 11 which in turn carries the stop 12. In the copying cylinder there is a piston 13 on a piston rod 14 which in turn is secured to the saddle 1 by a bolt 15.

The stop drum 11 is mounted on the bar 16 which in turn is fixed in the housing 8. The spring 17 urges the stop drum 11 in a direction towards the tool. The counter stop 18 is mounted on an arm 28 which is secured to the saddle 1 and which extends through an aperture 32 in the housing 8 from the saddle 1 to within range of the stop drum 11 in the interior of the housing 8. The cylinder 7 carries two trunnions 19 and 20 each of which in turn carries a ball bearing 21 and 22. Mounted on the housing 8 by means of these ball bearings is the lever 29. This engages, on the one hand, with a pin 23 in a groove 24 in the stop drum 11. On the other 'hand, it is in driving connection, by a pin 25, with a groove 26 which is on the spindle 27 of the distributing slide valve 10, not illustrated in detail, for the copying cylinder 7. Furthermore, the lever 29 also carries the feeler 30 which is opposite the template 31 as usual.

During the machining, a force K acts on the tool 6. This force K passes through the center of frictional forces 8 and can be divided into the transverse force Q and the longitudinal force L. The copying slide 5 is jammed against the lateral gib 3 by the transverse force Q, while the lateral gib 4 is relieved. As a result, the frictional force A appearing at the lateral gib 3 becomes considerably greater than the force B appearing at the other gib 4 which is in equilibrium with the force A through the center of frictional forces S. Since the force A is very great in comparison with the force B, the center of frictional forces S is still situated over the one gib 3. In order to prevent any jamming, the copying cylinder 7 is displaced beyond the center of frictional forces S, that is to say it is mounted at the one side of the copyingcylinder housing 8 over the one gib 3. As a result, space is provided to mount both the stop drum 11 and also the distributing slide valve 10 with their axes parallel at the other side of the housing 8.

The construction described leads to the following mode of operation:

During the making of a first cut, when the tool 6 with the copying cylinder 5 travels into machining position, this is reached as soon as the stop drum 11 is displaced against the pressure of the spring 17 through the striking of the stop 12 against the counter stop 18, until the lever 29 is displaced through the groove 24 and the pin 23 to such an extent that the distributing slide valve 10 is brought, by the pin 25, into such a position that the copying cylinder comes to a standstill and so the first rough out can be made. As a result of the fact that the stop drum 11 is likewise accommodated in the copyingcylinder 7, it is protected from dust. Nevertheless, it is easily accessible by removal of the housing 8 so that the stop 12 and possibly also other similar stops can be adjusted as usual.

It is thought that the invention and its advantages will be understood from the foregoing description and it is apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing its material advantages, the form hereinbefore described and illustrated in the drawings being merely a preferred embodiment thereof.

I claim:

1. A hydraulic copying attachment for a lathe, comprising a saddle having a dovetailed guide mounted thereon with two parallel gibs, a copying slide guided on said gibs having a center of frictional forces where the frictional forces on said two gibs are in equilibrium, a hous- 3 ing secured to said copying slide, a copying cylinder mounted in said housing, a distributing slide valve mounted in said housing with its axis parallel to said copying cylinder, a counter stop fixed to said saddle, a stop drum mounted axially displaceable on said copying slide to influence said distributing siide valve on impinging said counter stop, said copying cylinder being located axially behind said center of frictional forces and above one of said tWo gibs, said stop drum being located in said housing with its axis parallel to said copying cylinder and together with said distributing slide valve at one side of said copying cylinder.

2. An attachment as claimed in claim 1, wherein said housing has an aperture and said counter stop comprises an arm which extends through said aperture in said housing from said saddle to within range of said stop drum in the interior of said housing.

3. A hydraulic copying attachment for a lathe, comprising a saddle, a copying slide guided on said saddle, a

housing secured to said copying slide having an aperture, a copying cylinder mounted in saidhousing, a distributing slide valve mounted in said housing with its axis parallel with said copying cylinder, a counter stop fixed to said saddle, a stop drum mounted axially displaceable in said housing with its axis parallel to said copying cylinder to influence said distributing slide valve on striking said counter stop, said copying cylinder being situated at one side of said stop drum and of said distributing siide valve said counter stop comprising an arm which extends through said aperture from said saddle to within range of said stop drum in the interior-of said housing.

References bited UNITED STATES PATENTS 3,228,270 1/1966 Fenn et al. 82-14 GERALD A. DOST, Primary Examiner 

